import java.util.Scanner;

public class Main {

	static int target;
	public static void main(String argas[]){

		Scanner cin = new Scanner(System.in);

		target = cin.nextInt();
		long list[] = new long[target];

		for(int i=0;i<target;i++){
			list[i] = cin.nextLong();
		}
		cin.close();
		System.out.println(dfs(1,list[0],list));
	}

	static long dfs(int count,long sum,long array[]){
		if(count==target-1){
			if(array[count]!=0L){
				if(sum<0L){
					return Math.max(Math.max(sum*array[count],(long)sum/array[count]), Math.max(sum+array[count],sum-array[count]));
				}else{
					return Math.max(sum*array[count], Math.max(sum+array[count],sum-array[count]));
				}
			}else{
				return Math.max(0, sum+array[count]);
			}
		}else{
			if(array[count]!=0L){
				if(sum<0L){
					return Math.max(Math.max(dfs(count+1,sum*array[count],array),dfs(count+1,(long)sum/array[count],array)), Math.max(dfs(count+1,sum+array[count],array), dfs(count+1,sum-array[count],array)));
				}else{
					return Math.max(dfs(count+1,sum*array[count],array), Math.max(dfs(count+1,sum+array[count],array), dfs(count+1,sum-array[count],array)));
				}
			}else{
				return Math.max(dfs(count+1,0,array), dfs(count+1,sum,array));
			}
		}
	}

}